Cooling duct arrangement



March 9, 1965 J. scHMucK 3,172,397

COOLING DUCT ARRANGEMENT Filed June 7, 1962 3 Sheets-Sheet 1 Fig. 1

In vemor dOl-IAN scHMucK March 9, 1965 J. scHMucK 3,172,397

COOLING DUCT ARRANGEMENT Filed June 7, 1962 5 Sheets-Sheet 2 //1 vemordob AN jCl/MUCK March 9, 1965 J. SCHMUCK 3,172,397

COOLING DUCT ARRANGEMENT Filed June 7, 1962 3 Sheets-Sheet 3 Fig.3

TNVENTOR J OHA/VN SCHMUCK WWW ATTORNEYS United States Patent ,452 5Claims. or. r23-41.s2

The present invention relates to a cooling duct arrangement formulti-cylinder reciprocating combustion engine, more particularly, tosuch a cooling duct arrangement wherein cooling air from a blower on oneside of the engine is passed around cylinders and cylinder heads to beconducted away by a large conduit on the opposite side of the engine andformed in part by both the intake and exhaust ducts leading to thecombustion chambers which are on the same side of the engine with theseducts being constructed so as to have a common wall.

Multi-cylinder reciprocating combustion engines have previously beenprovided with exhaust ducts which extend transversely from the enginefor discharging the cooling air which has been circulated around thecylinder heads of the engine by a blower. The intake duct for thecooling air has usually been arranged on the same side of the engine onwhich the exhaust duct has been mounted. These cooling ducts aregenerally constructed from sheet material which is then attached toparts of the engine by various fastening arrangements. It has proved tobe extremely difficult to connect these ducts to the engine in such amanner that spaces are not formed between the edges of the ducts andparts of the engine.

These spaces, which are between the cast block of the engine and thecylinder heads which are usually provided with cooling fins, provideundesired passages for the leakage of the cooling air and also causeobjectionable noise by contacting the engine due to the vibrations ofthe engine when in operation. Not only is the noise objectionable, butthis repeated contact of the duets with the engine results in rapid wearof both these ducts and those portions of the engine being contactedthereby.

While it is possible to seal these spaces by elastic sealing compounds,this is not particularly desirable because the sealing compounds are notinexpensive and considerable amount of Working time is required toproperly apply the sealing compounds to these spaces. Further, thesealing compounds are rapidly fatigued as result of the hightemperatures to which they are exposed because of their contact with theengine casing and therefore frequent replacement of the sealing materialis necessary.

In those duct arrangements wherein the intake and/or the exhaustcollecting lines are arranged on the same side of the engine as theexhaust duct, further difficulties are encountered when either of theintake duct or the exhaust lines must pass through a wall of the exhaustduct. This means an opening must be provided in the sheet materialcomprising the exhaust duct and the respective line run therethrough.Thus, Whenever the exhaust duct must be removed, such as for maintenancepurposes, the line running through the opening in the wall thereof mustalso be disconnected. Further, spaces and leaks are inevitably formedbetween the wall of the pipe and the opening in the exhaust duct whichspaces are disadvantageous as discussed above.

In some cases the exhaust duct may be dispensed with and the cooling aircirculating around these cylinder heads may be discharged into theatmosphere. However, it is frequently desirable and economical toutilize this heated cooling air by discharging the cooling aircirculating from the cylinder heads into an exhaust duct. This heatedair 3,172,397 Patented Mar. 9, 1965 may then be passed through variousdrying installations as may be encountered in agriculture operations or,when the engine is being run in a closed room, into an exhaust line forremoving the air from the enclosure in which the engine is positioned.

It is therefore the principal object of the present inven tion toprovide a novel and improved cooling air duct arrangement formulti-cylinder reciprocating combustion engines.

It is a further object of the present invention to provide a simple andinexpensive exhaust duct for a multi-cylinder reciprocating combustionengine.

The disadvantages of the prior art as discussed above are avoided andthe foregoing objects are attained by the present invention. The ductarrangement of the present invention essentially comprises an exhaustduct for cooling air which is sufiiciently wide to span the extremeoutmost cylinder heads of an in-line reciprocating combustion engine.The exhaust duct extends transversely of the axis of the engine asrepresented by the crankshaft thereof and cooling air which iscirculated through cooling channels around the cylinder heads andcylinders is discharged through this exhaust duct. An intake duct to thecombustion chamber is provided which extends longitudinally of theengine and is arranged so that the bottom wall of the intake duct iscommon with the upper wall of the exhaust duct. A plurality ofconnecting passages extend from the bottom wall of the intake duct tothe combustion chambers in the cylinder heads. The common wall betweenthe intake ducts to the combustion chambers and the cooling air exhaustducts is provided with suitable fastening means for mounting the exhaustduct onto the cylinder heads of the engine. The bottom wall of theexhaust duct is mounted upon a shoulder extending from the block orcrankcase of the engine.

In another modification, the single line to the combustion chambers maybe utilized to exhaust the gases of combustion from the cylinder heads.In a further modification both the intake and exhaust lines leading tothe combustion chambers may be mounted on the wall of the exhaust duct.

Any of the foregoing structures will provide the results of the presentinvention since in all these structures the intake and/or exhaust lineto and from the combustion chambers are constructed as a unit togetherwith the exhaust duct for the cooling air. As a result the mounting ofthis duct arrangement is considerably facilitated since it is onlynecessary to mount the exhaust duct onto the cylinder heads.

Other objects and advantages of the present invention will be apparentupon reference to the accompanying description when taken in conjunctionwith the following drawings, wherein;

FIGURE 1 is an end view of an engine looking in the direction of thecrankshaft with a portion of the duct arrangement being shown in sectionfor purposes of clarity;

FIGURE 2 is a top plan view of the engine and duct arrangementillustrated in FIGURE 1; and

FIGURE 3 is a view similar to that of FIGURE 1 but showing a modifiedduct arrangement.

With respect to the drawings wherein like reference symbols indicate thesame parts throughout the several views there is illustrated aconventional multi-cylinder reciprocating combustion engine having acrankcase 1 from which are upstanding a plurality of cylinders 2 havingcooling fins thereon. Each cylinder comprises a cylinder head 3 andpositioned on each of the cylinder heads is a cylinder-head cover 4which encloses the necessary control elements such as the valve-rockerarms and springs therefor.

The cylinder heads are provided with cooling channels to circulatecooling air around, between, or through the cylinder heads andcylinders. The exhaust line of a cooling channel may be seen at 13 inFIGURE 1.

A blower 5 circulates the cooling air through the cooling channels.

The intake duct or manifold to the combustion chamber in the cylinderheads is indicated at 6 and extends longitudinally of the engine andparallel to the crankshaft thereof. The intake duct 6 is connected withthe cylinder heads by a plurality of elbow connections 7. As may be seenin FIGURE 1, the connections are 90 elbows and extend from the bottomwall 8 of the intake duct to the cylinder heads.

The bottom Wall 8 of the intake duct 6 is extended to the cylinder headsas may be seen in FIGURE 1 so as to form the upper wall of a cooling airexhaust duct 14. The wall 8 is essentially a plane which is connected tothe upper edge of the cooling air channels for circulating the coolingair in cooling relationship to the cylinder heads. Since the exhaustduct is fixedly connected with the cylinder heads, it can be appreciatedthat no special fastening members are necessary for connecting the upperwall 8 to the cylinder heads of the engine. This wall may be connectedwith the cylinder heads by machine screws or other suitable fasteningmeans.

The exhaust duct 14 also comprises a pair or lateral walls 9, dependingfrom the extreme ends of the upper Wall 8 and attached to a lower wall16. As may be seen in FIGURE 2, the lateral walls 9 are spacedsufiiciently far apart so as to extend to the outermost portions of theextreme cylinder heads of the engine. In this way all of the exhaustlines leading from the cooling channels of the cylinder heads arespanned by the exhaust duct and communicate therewith.

A ledge or shoulder 11 is provided on the crankcase 1 or may extend fromthe block of the engine to support the lower wall It). An external Range12 is provided at the outer ends of the wall defining the exhaust ductto facilitate connection to an exhaust line.

The intake duct 6 is of such a length so as to extend the length of theblock of the engine as may be seen in FIGURE 2 of the drawings. Theintake duct 6 together with its connections 7 may be manufactured as anintegral unit by casting or by welding the several conduits together. Tothis integral unit can then be attached to the lower and lateral wallsto define the cooling air exhaust duct.

It is pointed out that with this arrangement no openings are necessaryin the exhaust duct for the passage therethrough of the intake lineand/or an exhaust line.

Depending on the location of the exhaust lines leading from the cylinderhead cooling channels, the exhaust line for combustion gases may also beformed so that a Wall thereof is common with a wall of the exhaust duct14. The exhaust line may be formed in this manner either in addition tothe above-described formation of the intake duct, as may be seen inFIGURE 3, or to replace the intake duct. In FIGURE 3, an intake duct l-15 to the cylinder heads is mounted in addition to exhaust line 6 and isconnected by elbows 16 to the cylinder heads.

Thus it can be seen that the cooling duct arrangement of the presentinvention provides for a close fit with the casing of the engine so asto eliminate an gaps or spaces between the duct arrangement and theengine casing. With the fabrication of the intake duct assembly, theremaining elements of theexhaust duct can be easily connected to thecommon Wall of the intake duct to provide a simple yet effective coolingduct arrangement for combustion engines. The lower wall it of theexhaust duct may also be secured with the shoulder 11 by bolts or screwsso as to rigidly secure the duct arrangement to the engine.

Not only is this duct arrangement relatively inexpensive to manufactureand install, but the installed duct arrangement closely fits the coolingchannels of the engine so as to eliminate any leaks between .the'enginecasing and the duct arrangement.

It will be understood that this invention is susceptible to modificationin order to adapt it to dififerent usages and conditions and,accordingly, it is desired to comprehend such modifications within thisinventionas may fall Within the scope of the appended claims.

What is claimed is:

1. An air-cooled internal combustion engine comprising a series ofcylinders mounted on a crankcase, cylinder heads on said cylinders, aconduit attached to the cylinder head for communication with thecombustion chambers, and a cooling air exit conduit whose upper wall isintegral with the first-mentioned conduits, said exit conduit being wideenough to extend across the entire series of cylinders and cylinderheads and of sufficient depth to extend vertically across the cylinderand cylinder heads.

2. The engine of claim 1, in which the first-mentioned conduit includesa manifold integral with the upper wall of the exit conduit, the lowerwall of the manifold being coplanar with the upper wall of the exitconduit.

3. The engine of claim 1, in which the first-mentioned conduit includeselbows integral with the upper wall of the exit conduit and extendingdownwardly therefrom, the lower ends of said elbows being secured to thecylinder heads.

4. The engine of claim 1, in which the lower wall of the exit conduit isattached to the crankcase.

5. The engine of claim 1, in which the first-mentioned conduit is anintake conduit.

References Cited in the file of this patent UNITED STATES PATENTS1,264,281 Daugherty Apr. 30, 1918 1,313,252 Brooke Aug. 19, 19192,182,866 Gabrielson Dec. 12, 1938 2,270,912 Theodorsen Jan. 27, 1942

1. A AIR-COOLED INTERNAL COMBUSTION ENGINE COMPRISING A SERIES OFCYLINDERS MOUNTED ON A CRANKCASE, CYLINDER HEADS ON SAID CYLINDERS, ACONDUIT ATTACHED TO THE CYLINDER HEAD FOR COMMUNICATION WITH THECOMBUSTION CHAMBERS, AND A COOLING AIR EXIT CONDUIT WHOSE UPPER WALL ISINTEGRAL WITH THE FIRST-MENTIONED CONDUITS, SAID EXIT CONDUIT BEING THEWIDE ENOUGH TO EXTEND ACROSS THE ENTIRE SERIES OF CYLINDERS AND CYLINDERHEADS AND OF SUFFICIENT DEPTH TO EXTEND VERTICALLY ACROSS THE CYLINDERAND CYLINDER HEADS.